Add service input plugin for OpenConfig streaming telemetry (#2292)

plugins/inputs/jti_openconfig_telemetry/collection.go

@@ -0,0 +1,63 @@
+package jti_openconfig_telemetry
+
+import "sort"
+
+type DataGroup struct {
+	numKeys int
+	tags    map[string]string
+	data    map[string]interface{}
+}
+
+// Sort the data groups by number of keys
+type CollectionByKeys []DataGroup
+
+func (a CollectionByKeys) Len() int           { return len(a) }
+func (a CollectionByKeys) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+func (a CollectionByKeys) Less(i, j int) bool { return a[i].numKeys < a[j].numKeys }
+
+// Checks to see if there is already a group with these tags and returns its index. Returns -1 if unavailable.
+func (a CollectionByKeys) IsAvailable(tags map[string]string) *DataGroup {
+	sort.Sort(CollectionByKeys(a))
+
+	// Iterate through all the groups and see if we have group with these tags
+	for _, group := range a {
+		// Since already sorted, match with only groups with N keys
+		if group.numKeys < len(tags) {
+			continue
+		} else if group.numKeys > len(tags) {
+			break
+		}
+
+		matchFound := true
+		for k, v := range tags {
+			if val, ok := group.tags[k]; ok {
+				if val != v {
+					matchFound = false
+					break
+				}
+			} else {
+				matchFound = false
+				break
+			}
+		}
+
+		if matchFound {
+			return &group
+		}
+	}
+	return nil
+}
+
+// Inserts into already existing group or creates a new group
+func (a CollectionByKeys) Insert(tags map[string]string, data map[string]interface{}) CollectionByKeys {
+	// If there is already a group with this set of tags, insert into it. Otherwise create a new group and insert
+	if group := a.IsAvailable(tags); group != nil {
+		for k, v := range data {
+			group.data[k] = v
+		}
+	} else {
+		a = append(a, DataGroup{len(tags), tags, data})
+	}
+
+	return a
+}